The present invention relates to the dispensing of beverages and in particular to the dispensing of beverages which form a head. It is therefore of particular relevance to the dispense of beer, including lager, ale, porter and stout, but is also relevant to the dispense of other alcoholic and non-alcoholic beverages with a dissolved gas content.
There are many types of beverage which form a head when dispensed into a drinking vessel such as a glass, and in many circumstances there is a need to control the size of the head. This can be simply to meet the tastes of the person who will drink the beverage, or it can be to meet legal requirements, in particular where a beverage with a head is being sold by volume in a drinking vessel.
It is known, for example from WO 01/36582, to dispense a beverage into a drinking vessel using a dispensing apparatus in which the vessel is supported on a stand or table, and a predetermined volume of beverage is dispensed into the vessel from a dispense nozzle. However there are various factors which can affect the size of the head on a beverage dispensed in this way. This can be a problem because the amount of head on some beverages sold by volume is controlled by law, and also because the size of head on some beverages is a matter of personal taste and it is therefore desirable to be able to provide the customer with exactly the amount of head he or she prefers
Accordingly the present invention provides a method of dispensing a beverage into a drinking vessel having a base and a side wall, the method comprising the steps of supporting the vessel, rotating the vessel, and directing a stream of the beverage against the side wall of the vessel while the vessel is rotating.
The stream of beverage preferably impacts the side wall of the vessel at an angle of between 20xc2x0 and 40xc2x0, more preferably between 30xc2x0 and 40xc2x0.
The vessel is preferably of circular section, and is preferably rotated about its central axis.
The stream of beverage may be projected from a nozzle in a direction which is inclined to said axis. Alternatively the stream of beverage may be diverted after it is emitted from the nozzle.
Conveniently the vessel may be supported such that the axis is vertical, but it can also be supported so that the axis is inclined to the vertical.
Preferably the vessel is rotated such that its side wall has a direction of rotation, and the stream of beverage is directed such that, when it contacts the side of the vessel, it has a component of travel in said direction of rotation. This can help to smooth the flow of beverage in the vessel and thereby help to control the amount of head produced.
The rate of dispense of the beverage, the rate of rotation of the vessel, and the angle at which the stream of beverage impacts the side of the vessel may each be controlled to control the size of the head, and may also be varied during dispense of the beverage.
The impact angle of the stream of beverage on the side of the vessel may be controlled by controlling, and optionally also by varying, the angle at which the vessel is supported, the angle at which the nozzle is arranged, or the rate at which the beverage is dispensed.
Preferably the dispensing has a plurality of parameters associated with it, and the method comprises monitoring one of the parameters and controlling the dispensing so as to control the size of the head.
The parameter which is monitored may be, for example, the dispense temperature at which the beverage is dispensed, a storage temperature at which the beverage has been stored, for example in a cellar or in a tank below a drinks bar, or an ambient temperature of the environment in which the beverage is dispensed.
The present invention further provides apparatus for dispensing a beverage into a drinking vessel having a base and a side wall, the apparatus comprising a support for supporting the vessel, and a nozzle for dispensing a stream of the beverage into the vessel, wherein the support is arranged to rotate the vessel and the nozzle is arranged to direct said stream against the side wall of the vessel while the vessel is rotating.
Preferably the support defines an axis of rotation about which the vessel can be rotated and the nozzle is arranged to direct said stream in a direction which is inclined to said axis.
Preferably the apparatus is arranged to dispense the beverage into the vessel such that a head forms on the beverage, wherein the apparatus is arranged to control the size of the head.
Preferably the apparatus is arranged so that it can control the size of the head to any of a plurality sizes, and further comprises an operator input arranged to allow an operator to select one of said sizes of the head.
Preferably the apparatus is arranged to dispense the beverage in any of a plurality of volumes and, for at least one of said volumes, the apparatus can control the size of the head to any said plurality of sizes. For example of the apparatus is arranged to dispense the beverage in volumes of one pint or a half pint, each one of these measures may be chosen with any of a plurality of different sizes of head.
Preferably the apparatus further comprises at least one sensor for sensing a value of at least one parameter relating to the dispensing of the beverage, and a controller arranged to adjust the apparatus in response to the value of said at least one parameter to control the size of the head.
The support may be arranged to support the vessel such that its side wall is inclined at an angle with the vertical, and to vary said angle while the beverage is dispensed. Furthermore, said angle may be controlled to control the size of the head formed on the beverage.